1. Field of the Invention
This invention relates to pliable and conformable gloves such as surgical gloves and more particularly to protective gloves used in medical related procedures and facilities made from a polyurethane elastomer.
2. The Prior Art
Surgical gloves are made of very thin elastomeric materials such as vulcanized natural rubber and the like and are sized to provide a tight fit forming a skin-like sheath on the hand of the wearer. The objectives of surgical glove manufacturers are to provide a glove which will impart maximum tactile sensitivity to the wearer without impairing his facility of manipulation while at the same time protecting both the wearer and the patient from cross-contamination or infection.
There are however, a number of undesirable characteristics of the prior art gloves. One such undesirable characteristic of the gloves manufactured from vulcanized natural rubber is that the gloves may cause an adverse reaction to the skin of the wearer. Approximately 5% of all surgeons and medical personnel suffer from some type of dermatitis caused by an allergy or sensitivity to the vulcanized natural rubber.
Because of their skin tight fit and nature of the vulcanized natural rubber, dry lubricants such as talc have been used to permit surgical gloves to be easily placed on the hands of the wearer. Unfortunately, talc has been known to irritate skin when brought into contact with it, thereby aggravating the dermatitis problem encountered with vulcanized natural rubber.
In addition to the skin problems encountered with surgical gloves manufactured from vulcanized natural rubber, the gloves exhibit limited physical strength and are easily torn or punctured. The increasing risk of infection encountered by health care workers in contact with contaminated body fluids from patients with infectious diseases such as AIDS makes it imperative that gloves worn by these workers have a high degree of tear and puncture resistance so as to provide maximum protection from exposure to dangerous organisms contained in these body fluids.
Another undesirable characteristic of surgical gloves manufactured of vulcanized natural rubber is the fact that they frequently contain tiny pin-holes. By virtue of the molecular make-up of vulcanized natural rubber and the dip process by which surgical gloves are normally manufactured, such tiny pin-holes do occur. Although such pin-holes are very small, they are normally large enough to allow transmission of very small blood borne viruses smaller than 10 microns, such as the AIDS and Hepatitis B viruses.
In addition to the above undesirable characteristics, hand fatigue and poor finger-tip sensation are prevalent problems due to the elastic properties of the vulcanized natural rubber.
One approach to overcome the allerginicity problem has been to manufacture surgical gloves from polyurethane compositions which are hypoallergenic. For example, McGarry, Jr. et al, U.S. Pat. No. 4,463,156 discloses the manufacture of hypo-allergenic surgical gloves from polyurethane elastomers which are the reaction products of an aromatic or alicyclic polyisocyanate and a long chain diol (500-5000 average molecular weight) that is cross-linked with a polyhydroxy cross-linking agent. Although elastic gloves manufactured from polyurethane elastomers of the type disclosed in U.S. Pat. No. 4,463,156 are hypoallergenic, a number of disadvantages are encountered with such gloves as well. For example, due to the use of a cross-linking agent in the preparation of the polyurethane elastomer, there results a glove manufacturing process that is costly, slow, and relatively complex when compared to prior glove manufacturing processes. In addition to higher glove manufacturing costs, gloves manufactured using the cross-linked polyurethane compositions when compared to vulcanized natural rubber gloves exhibit less conformity to the wearer's hand when worn. Further, the cross-linked nature of polyurethane compositions limits approval for medical grade use.
In addition to the above disadvantages of surgical gloves manufactured of cross-linked polyurethane, such gloves are rather rigid causing a high degree of hand fatigue and providing very poor finger-tip sensation.
In view of the above considerations, there is a need in the art for a surgical glove that is non-allergenic or hypoallergenic, exhibits superior tear and puncture resistance, does not tend to form pin-holes during manufacturing, minimizes hand fatigue and provides optimum finger-tip sensation.